The zeroing of a page of a arbitrary order in page_alloc.c and in hugetlb.cis currently done one page at a time. It may be beneficial tozero large areas of memory in one go. The following patch introducesclear_pages that takes an additional order parameter. clear_pages is only usedwhen __HAVE_ARCH_CLEAR_PAGES has been defined by an architecture.

clear_pages functions have been provided for ia64, i386, sparc64 and x86_64.This version was tested by me on ia64, i386 and x86_64.